Building pondscapes for amphibian metapopulations

Area of Science:

• Ecological restoration
• Amphibian metapopulation dynamics
• Conservation science

Background:

• The success of constructed ponds for amphibian conservation relies on site selection and habitat characteristics.
• Understanding metapopulation dynamics is crucial for effective amphibian conservation strategies.

Purpose of the Study:

• To investigate the influence of pond and landscape characteristics on amphibian colonization and persistence in constructed ponds.
• To evaluate the effectiveness of different connectivity metrics in predicting amphibian metapopulation dynamics.

Main Methods:

• Dynamic occupancy models were fitted to 20 years of monitoring data from a Swiss pond construction program.
• Effects of pond size, hydroperiod, surrounding forest cover, and various connectivity metrics were analyzed.
• Colonization and persistence probabilities for 12 amphibian species were quantified.

Main Results:

• Population connectivity, particularly population density and proximity to existing populations, was a stronger predictor of amphibian dynamics than structural connectivity.
• Ponds located near 2-4 occupied ponds within 0.5 km showed over 3.5 times higher target species incidence.
• Larger pond surface area (≥100 m²), temporary drying, and surrounding landscapes with ≤50% forest cover benefited multiple target species.

Conclusions:

• Population connectivity is a key factor mediating amphibian persistence in newly established ponds, indicating potential source-sink dynamics.
• Simple connectivity metrics like nearest neighbor distance and population density are effective for site selection.
• Habitat diversity, including pond characteristics and landscape composition, is essential for fostering amphibian diversity at the landscape scale.